Unfortunately, I wouldn’t expect the average guy to know how to tell whether a UV bulb is safe (regular non-quartz glass helps a lot) or that dangerous ones are sold without warnings.
You hire trained professionals for this kind of thing. There are literally entire companies who specialize in putting together these kinds of events safely, every single day.
A professional stage lighting designer or theatrical electrician would absolutely know that this is a risk.
All bets are off if you're using LEDs.